updated 07:54 pm EDT, Wed July 30, 2014

Last week, one of the largest mobile carriers in the United States announced it would begin throttling some unlimited accounts that access 4G LTE. Verizon stated that it would begin the effort in October, but it would be limited to only the top five percent of data users on unlimited plans. While the slowdown won't have an effect on all LTE customers, Federal Communications Commission (FCC) Chairman Tom Wheeler believes that the new policy is running afoul of several regulations.

Calling the slowdown "network optimization practices" under the idea of creating an improved reliability, Verizon says that it will manage unlimited accounts to optimize the network. However, it adds that this will only occur in areas and during times that are seeing a high demand. The speed reduction is said to be "the smallest possible impact," and only occurs when optimization is necessary.

The carrier states data speed management happens once a user with an unlimited plan reaches a certain threshold in data use. Verizon maintains that this management isn't "throttling." If a customer doesn't want to run the risk of being subject to management, they simply need to dump their unlimited plan for a metered one.

"If you're on an unlimited data plan and are concerned that you are in the top five percent of data users, you can switch to a usage-based data plan as customers on usage-based plans are not impacted," Verizon said.

For Wheeler, the news of the network management wasn't a welcome change. In a letter to Verizon CEO Daniel Mead obtained by Ars Technica, Wheeler said that he is "deeply troubled" by the announcement. Wheeler specifically points to issues with the way the company uses the term "network optimization," which it uses as another way to describe network management. The problem stems from the idea of reasonable management as defined by the FCC.

"'Reasonable network management' concerns the technical management of your network; it is not a loophole designed to enhance your revenue streams," said Wheeler. "It is disturbing to me that Verizon Wireless would base its 'network management' on distinctions among its customer's data plans, rather than on network architecture or technology."

The letter continues, reminding Mead of what the FCC considers reasonable, as it pertains to an appropriate, legitimate purpose based on network architecture, technology and broadband access. Wheeler points out that a legitimate purpose could be tied to security, unwanted traffic or "reducing or mitigating the effects of congestion on the network."

Wheeler asks the Verizon CEO to answer a series of questions to defend the company's policy change, including why the choice is based on plans rather than technology or architecture. He also asks why the same sorts of reductions seen on 3G networks are being applied to the "more efficient 4G LTE network." His final question brings up the carrier's obligations under the 700 MHz C Block rules, which states the Verizon "may not deny, limit or restrict the ability of end users to download and utilize applications of their choosing on the C Block networks." He requests the CEO answer how the business practice is allowed under the 2010 Open Internet rules, including the transparency rule.

"I know of no past Commission statement that would treat as 'reasonable network management' a decision to slow traffic to a user who has paid after all, for 'unlimited' service."